1. Field of the Invention
The present invention relates to a grinding machine of the type that a rotating grinding wheel is moved toward and away from a rotating workpiece thereby to grind a cylindrical surface of the workpiece.
2. Discussion of the Related Art
Heretofore, there has been known a grinding machine wherein a wheel head rotatably carrying a grinding wheel is mounted on a bed through a slide mechanism to be movable toward and away from a work support drive mechanism including a work head and a tailstock and wherein a workpiece rotatably supported between the work head and the tailstock is ground with the grinding wheel with coolant being ejected from a coolant nozzle to a grinding point. In the known grinding machine, a cover device is provided for preventing coolant and grinding chips from splashing as well as for protecting the grinding machine against dust.
For example, Japanese unexamined, published patent application No. 2003-117828 describes a grinding machine wherein an overall cover is provided for covering the whole part of a work head, a tailstock, a wheel head and a slide mechanism for the wheel head which are arranged on a bed. In the known grinding machine, a slide door which is selectively opened or closed when a workpiece is loaded or unloaded is provided at a front center of the overall cover, and folding double doors are provided at both lateral surfaces of the overall cover so that maintenance or service works on the devices including the slide mechanism for the wheel head can be carried out easily.
However, in the foregoing known grinding machine, when maintenance or service work is to be carried out on mechanisms such as the slide mechanism for the wheel slide or the like which are arranged at relatively rear parts of the bed, such maintenance or service work has to be done with either or both of the folding double doors opened in dependence on the locations at which such maintenance or service works are carried out. Further, in addition to the slide door for loading and unloading the workpiece, secondary doors are provided for the maintenance or service work on the work head and the tailstock, and they have to be kept opened while maintenance or service works are performed on the work head and the tailstock. Therefore, for services of plural portions of the grinding machine, it was necessary to open the plural doors prior to such services and to close upon completion of the same, and this made such services laborious to carry out. In particular, it is a recent trend that the floor space for installation of one grinding machine is reduced. Thus, where a plurality of grinding machines are installed on a factory floor, a space between a grinding machine and the next is set narrow, thereby making it difficult to perform wheel exchange and service with the plural doors at the lateral surfaces of the overall cover being kept opened.